The invention relates to a device for equalizing the mass forces of reciprocating piston, crankshaft engines, and in particular, the mass forces of Order II of four-cylinder, four-stroke, in-line engines.
It is known that the operation of reciporcating piston, crankshaft engines produces mass forces and moments due especially to the reciprocating parts, such as pistons, connecting rods and the like, which forces are more or less imbalanced depending on type of engine as well as number and arrangement of crankshaft cranks. These imbalanced forces affect the performance and quietness of the engine.
Mass forces of Orders I and II can be balanced by means of revolving counterweights and/or pairs of counterweights. Thus, there is a known arrangement, called A Lanchester balance, for equalizing the mass forces of Order II in piston engines, particularly four-cylinder, four-stroke, in-line engines. In this arrangement, two counterweighted auxiliary shafts rotate in opposite directions at twice the speed of the crankshaft. This mass balancing system, however, requires a comparatively high mechanical outlay and, because of its length, great structural strength. Furthermore, the high speed of the auxiliary shafts and their drives creates considerable noise.